Hemophilia gene mutations are caused by sex chromosome-linked recessive mutations and are passed on to the next generation. Both hemophilia A and B are typical sex chromosome (X chromosome) linked recessive disorders. There are four scenarios: a male hemophiliac married to a normal woman, a normal man married to a carrier of the hemophilia gene, a hemophiliac married to a female carrier, and a male hemophiliac married to a female patient, all of which have the potential for their offspring to develop the disease or to become carriers of the blood disease gene. Hemophilia A is also known as FⅧI deficiency, and Hemophilia B is also known as IX deficiency. The gene locus for PvMm is at the end of the long arm of the X chromosome (Xq28), and the gene locus for FIX is at the end of the long arm of the X chromosome (Xq27). Consult a hematologist for specific knowledge.